Asynchronous I2S FIFO project, an ultimate weapon to fight the jitter

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iancanada

iancanada

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Joined 2009
twitter.com/iancanadaTT
Paid Member
Eldam said:
Any testimonials here about how managing the baterry set for Clock board ?

Is there a manual for it as well ? I discover too late I need also adaptator for Crystek 957 (thanks LudwigHaus for the tip)... so if any have a good experience to share about those battery environment for the Clock2, it will be much appreciated :)

ANd also how long battery will last ? - but I understood they can be reloaded with the good Ian sourced in local for his needs if I remember ! LiFePo something iirc ! but not sure...)
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Hi Eldam,

It's a 3.4V A123 26650 LiFePo4 battery cell. It's the best low noise power supply for clock board I have so far.

The total running time will be more than 12 hours for Dual XO I/II, I don't have problem charge it over night via the battery manage board when main power is off. The battery will be killed if the voltage is lower than 2V. So, has to be very carefully about over discharge.

Regards,
Ian
 
TimCurtis

TimCurtis

Member
Joined 2012
moodeaudio.org
Hi,

Moode release 2.5 (Jan 2016) includes selection for IanFIFO II :)

I'm planning a 2.5 test release in December. Download available at moodeaudio.org

Regards,
Tim
 

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supra

Member
Joined 2004
supratek.com.au
Eldam said:
Well because the low price and the testimonial of Supra, I decided to test the RaspBerry (easy also to reduce noise by battery feeding) and asked Ian the uf-l board and plug for it in my yesterday order ! I lurk towards Volumio 2 as a nice plug & play distro... at least better than a Windows with asio driver I assume ! But this is already an other story !

I'm not so happy with the Linux distro I have in my Synology Nas to feed the Wave I/O and Ian's devices before the AYA2 2014 ! Not so pleasant interface to use ! It's a pitty as Synology is a plug&play (and forgett) device with also an usb output !

Let's come back to Fifo / clock and battery management !
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Eldam
Try Moode, I had no success with rune or volumio, Moode is much better and could even be important to sound quality (yes I know, bits are bits)
 
M

marcus1

Member
Joined 2004
Hi Supra

I'm interested in running my Rpi from batteries - how do you use batteries in your setup?

Thanks

supra said:
No upsampling. Usb creates a substantial roadblock, which I was not aware of till now. Direct I2S, no usb, is a revelation, however the raspberry on its own is very jittery, and not really hi fi, but when combined with Ians FIFO , isolator, good clocks, and the AYA 1541 running in sim data it is beyond anything else I've heard via digital. Also running the raspberry from batteries which I suspect is important.
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iancanada

iancanada

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Gitaarwerk said:
Would a power bank also work for the clock board with some resistors? :) I already got a lineair PSU (SqueezeBox Upgrade) for the raspberry.
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Be careful with the switching mode DC-DC if there is one in a power bank. It could be very noisy some times. Linear would be a much better solution for a clock oscillator or VCO.

Ian
 
D

Dimdim

Member
Joined 2008
TNT said:
OK, so no Ian buffer involved in these tests.. ?

I don't think the Soerkris would benefit form an Ian buffer really...

//
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Nope, no Ian buffer in my case.. Just a good ol' 9018 with its internal DPLL.

The Soekris' FIFO buffers about 1mS of music (can't really remember at what SR). That should take care of most problems, plus Ian's buffer would probably be hampered by the (non-bypassable) FIFO of the Soekris anyway.
 
TNT

TNT

Member
Joined 2003
Paid Member
Dimdim said:
Nope, no Ian buffer in my case.. Just a good ol' 9018 with its internal DPLL.

The Soekris' FIFO buffers about 1mS of music (can't really remember at what SR). That should take care of most problems, plus Ian's buffer would probably be hampered by the (non-bypassable) FIFO of the Soekris anyway.
Click to expand...

And the the digital PLL is set to 120 seconds if I recall correctly- that way it comes away with such a small amount of memory. Clever, but not as good as Ians "all in solution" ;)

//
 
E

Eldam

Banned
Joined 2012
Did anyone try to putt the uf-l adaptator for Raspberry from Ian on an OdroidC1+ ? Same type of pcb plug and I2S pins arrengement ?

About the distros for such ARMs devices : would you confirm they don't sound the same ???? Some with MPD (music player daemon) (i.e. RunneAudio, etc) and some with new player ? Something is worrying me about a same plateform with the same output sounding different with two different AMR distros ?!

I can believe I2S output to give a different result than USB, but 2 distros ? WHat am I missed ? (Don't want to troll, just a simple phrase to explain maybe enough for me, I saw elswhere Peterma member to have also a better result according to him by outputting with a mini-PC and I2S pins !)

thanks in advance, regards

Eldam
 
G

Gitaarwerk

Member
Joined 2014
Eldam said:
Did anyone try to putt the uf-l adaptator for Raspberry from Ian on an OdroidC1+ ? Same type of pcb plug and I2S pins arrengement ?

About the distros for such ARMs devices : would you confirm they don't sound the same ???? Some with MPD (music player daemon) (i.e. RunneAudio, etc) and some with new player ? Something is worrying me about a same plateform with the same output sounding different with two different AMR distros ?!

I can believe I2S output to give a different result than USB, but 2 distros ? WHat am I missed ? (Don't want to troll, just a simple phrase to explain maybe enough for me, I saw elswhere Peterma member to have also a better result according to him by outputting with a mini-PC and I2S pins !)

thanks in advance, regards

Eldam
Click to expand...

Not sure about the USB part other than noise and bandwidth.. but there is the kernel profiles. They actually will sound different, even tho the sound is bit-perfectly played.

Fingers in the Pi | ???The Audio Standard
 
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J

Julf

Member
Joined 2011
Eldam said:
About the distros for such ARMs devices : would you confirm they don't sound the same ???? Some with MPD (music player daemon) (i.e. RunneAudio, etc) and some with new player ? Something is worrying me about a same plateform with the same output sounding different with two different AMR distros ?!
Click to expand...

Unless one of them does resampling or gain adjustment (badly).

I don't think we have any verified evidence that two bit-perfect distros sound different.
 
E

Eldam

Banned
Joined 2012
But if it's resynchronised by the local receiver after reception (by the I2S to USB pcb), you should hear no difference at all ? So no packett loss, but not the same quantity of noise or jitter injected in the stage after ?

The stage after : USB to I2S is removed if you connect directly the mini-pc to a FIFO, so how to compare ?

The only thing I see is you have a direct 50 ohms connection if you use uf-l wires instead the 90 ohms USB ?

Or the USB to I2S pcb changes something (local impedance between the stage before and the one after, own supply of the pcb, ...?,... , etc.

I will try as well the size of the buffer, but I will not see where it can affect jitter/noise as here this is not on the fly treatment, or any lost of packett at those length or weight (or the buffer is a xxxxx !

Interressant subject, maybe it deserves a thread in the PC parts of DIYA. I suspect it's all analogic pcb/active parts/passive parts/interstage connexions related if there is a difference. Where to dig and measure is the subject !
 
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S

supra

Member
Joined 2004
supratek.com.au
Dimdim said:
Nope, no Ian buffer in my case.. Just a good ol' 9018 with its internal DPLL.

The Soekris' FIFO buffers about 1mS of music (can't really remember at what SR). That should take care of most problems, plus Ian's buffer would probably be hampered by the (non-bypassable) FIFO of the Soekris anyway.
Click to expand...

I've got a Soekris dac, it doesn't come even remotely close to whats possible with Ians gear, imo. Good value maybe but mediocre sound.
 
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